In vitro compatibility study of cephalosporin with intraocular irrigating solutions and intracameral medications.

BACKGROUND: To study the compatibility of cephalosporins with intraocular irrigating solutions and intracameral medications commonly used in cataract surgery. DESIGN: The was an in vitro experiment conducted in the Research Laboratory of the Department of Microbiology, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. SAMPLES: Three cephalosporins--cefazolin, cefuroxime and ceftazidime--were separately diluted and mixed with irrigating solutions and intracameral medications to form 192 samples and 12 control solutions. METHODS: The cephalosporins were dissolved in normal saline and further diluted to the concentration of 1 mg in 0.1 mL with normal saline, Ringer's solution, balanced salt solution and fortified balanced salt solutions. These were mixed with balanced salt solutions or fortified balanced salt solutions, with adrenaline, acetylcholine or carbachol and kept at 37°C for 2 h. The concentrations of free cephalosporins were measured with rapid high-performance liquid chromatography at baseline (0 h) and at 2 h. MAIN OUTCOME MEASURES: Free concentrations of cephalosporins at 2 h were compared with mean baseline (0 h) value. A difference of 3 standard deviations or more was considered statistically significant. RESULTS: At 2 h there was a significant drop in the cefuroxime concentration in preparations in which cefuroxime was diluted with normal saline (P < 0.01). In all preparations, the final concentrations of cephalosporins were higher than the minimal inhibitory concentrations (MIC(90)) for microbials commonly isolated from the external eye. CONCLUSION: Cefazolin, cefuroxime and ceftazidime were compatible with irrigating solutions and intracameral medications commonly used in cataract surgery.

Central serous chorioretinopathy after sequential argon-neodymium: YAG laser iridotomies.

Laser peripheral iridotomy is the standard treatment for acute angle-closure glaucoma. A patient with acute angle-closure glaucoma who developed central serous chorioretinopathy after uneventful laser iridotomies is described. Central serous chorioretinopathy occurring after sequential argon-neodymium:YAG laser peripheral iridotomy is a novel complication in the English literature and is related to the stress induced by both the initial disease and the subsequent procedure, particularly in psychologically susceptible individuals.

Descemet stripping endothelial keratoplasty: effect of the surgical procedure on corneal optics.

PURPOSE: To determine the changes in corneal optical performance after posterior lamellar corneal transplantation. DESIGN: Retrospective case series. METHODS: The anterior segment in four eyes of four patients who underwent Descemet stripping endothelial keratoplasty (DSEK) with cataract extraction and intraocular lens (IOL) implantation were imaged with the Visante anterior segment optical coherence tomography [OCT] (Carl Zeiss Meditec, Dublin, California, USA). The curvature of the posterior surface of the donor graft was compared with that of the host cornea, and corneal thickness was measured. RESULTS: All eyes had a hyperopic refractive error after surgery. The posterior corneal curvature after surgery was more than that before surgery. Average preoperative keratometry was 43.4 diopters (D), and after surgery, it was 42.8 D using keratometry. However, when the postsurgical corneal power was calculated using the Gaussian optics method, the average value was 40.8 D. CONCLUSIONS: The addition of a donor corneal graft to the posterior surface of decompensated corneas may lessen the effective optical power of the cornea and may have implications for IOL power calculations in these eyes.

Spontaneous closure of anterior capsule tear.

We report a case of anterior capsule tear that was closed spontaneously by fibrotic tissue during the postoperative period. The tear was inadvertently created during intraocular lens (IOL) implantation in the capsular bag. The IOL remained stable in the postoperative period, with excellent centration and no compromise in vision.

Retrocapsular lens matter in uneventful phacoemulsification: does it really exist?

PURPOSE: To have the first cytopathological evaluation of any lens matter fragments within retrocapsular anterior vitreous in those patients undergone uneventful phacoemulsification in Prince of Wales Hospital, Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong. METHODS: Thirty patients with cataracts and various vitreoretinal conditions that required combined surgery were recruited. After the uneventful clear corneal phacoemulsification, three sclerotomies including infusion port were created with cautions against any inadvertent leakage of vitreal content. The anterior vitreous at retrocapsular space was harvested by a special 'round-the-clock' dry vitrectomy into a special specimen reservoir hub and syringe. The aspirate was immediately fixed in 50% ethanol and together with a masked positive control sent for cytocentrifugation processing. The microscope slides of the anterior vitreal content and control were stained with haematoxylin and eosin and papanicolaou. Positive controls were collected from the effluent fluid of the phaco cassettes right after the phacoemulsification. The samples were masked and examined by an experienced pathologist for any cytopathological evidence of lens matter. RESULTS: Out of 30 patients, three suspicious cases of retrocapsular lens fragment were noted by retroillumination on the operating table. However, all the anterior vitreous specimens were negative for lens matter whereas all the controls were positive after cytopathological verification. CONCLUSIONS: This is the first cytopathological study objectively indicating low likelihood of the postulation that retrocapsular lens matter occurred after uneventful phacoemulsification.

Retention of silicone oil droplets from ophthalmic viscosurgical devices in the drainage angle of 2 eyes.

We report the outcome in 2 eyes of 2 patients with retained silicone oil droplets in the anterior chamber drainage angle after the use of an ophthalmic viscosurgical device (OVD) during cataract surgery. Silicone oil droplets were observed when the OVD was injected into the anterior chamber during phacoemulsification. Despite removal by irrigation and aspiration, droplets were observed in the anterior chamber during the immediate postoperative period. At 15 months, they were observed in the drainage angle. The retained silicone did not produce untoward side effects in the eyes. Silicone oil is a common contaminant in OVDs but appears to be inert and harmless when retained in small amounts in the anterior chamber drainage angle.

Topical anesthesia-induced keratopathy after laser-assisted subepithelial keratectomy.

A 42-year-old woman had uneventful bilateral laser-assisted subepithelial keratectomy (LASEK) to correct myopia. She experienced intense pain in the first postoperative week and obtained topical oxybuprocaine for pain relief. Subsequently, she developed bilateral persistent corneal epithelial defects, epithelial edema, and bullae that failed to heal with bandage contact lens and topical lubricants. Over the next 4 months, there was progressive corneal stromal thinning and descemetocele formation in 1 eye, requiring application of cyanoacrylate glue, and stromal edema and scarring in the other eye, which resulted in a visual acuity of counting fingers. Investigations did not reveal associated infection or an underlying immunological disorder; however, the patient admitted to excessive use of topical anesthetic eyedrops in the post-LASEK period. She subsequently had penetrating keratoplasty and lens extraction with IOL implantation in the right eye. The left eye healed with central corneal scarring. This case illustrates that serious sight-threatening complications may occur after LASEK due to abuse of topical anesthetic agents.

A case series of contact lens-associated Fusarium keratitis in Hong Kong.

PURPOSE: To report the clinical features and management outcomes of a cluster of Fusarium keratitis in patients that used the Bausch & Lomb ReNu MostureLoc contact lens solution. METHODS: Retrospective case series. RESULTS: In a 1-year period starting from June 2005, we treated 12 patients with unilateral Fusarium keratitis in our tertiary care center. All patients were contact lens users that used ReNu MostureLoc contact lens solution and had no other specific predisposing conditions. Microbiological examination yielded growth of Fusarium spp. in 7 patients from corneal scrapings at presentation and from 3 patients in subsequent corneal specimens. For 2 other patients, fungi were not detected from corneal scrapings, but Fusarium spp. were isolated from their contact lenses. The infections were treated with topical natamycin and amphotericin B eye drops and with systemic itraconazole in 8 patients. The infection resolved with medical treatment in 8 eyes, a conjunctival flap in 1 eye, and a therapeutic corneal graft in 1 eye. Two eyes required tectonic corneal grafts for perforation. Two of the 3 corneal grafts failed because of graft rejection. Final visual acuities ranged from count fingers to 1.0. CONCLUSIONS: This cluster of Fusarium keratitis seems to be related to the use of the ReNu MoistureLoc contact lens solution. The cure rate with medical therapy was 66%. However, corneal scarring limited visual recovery. This episode highlights the need for clinical vigilance when dealing with corneal infiltrates in contact lens users.

Acyclovir-induced nephrotoxicity in a patient with acute retinal necrosis.

A 50-year-old woman developed rapidly progressive acute renal failure on the first day after the administration of intravenous acyclovir for acute left retinal necrosis. Intravenous acyclovir was stopped and replaced with intravitreal injections of ganciclovir sodium (2 mg/0.05 mL) and foscarnet (1.2 mg/0.05 mL) 3 times per week for 4 weeks. Acyclovir-induced renal impairment can be reversed if recognised early and treated with careful, timely body fluid replacement. The necrotising retinitis responded well to intravitreal antiviral agents. No complications were seen at the 6 months' follow-up. Constant vigilance is essential for avoiding acute renal failure when treating ophthalmic conditions with intravenous acyclovir. Systematic monitoring of renal function, urine output, and characteristic symptoms like loin pain is warranted.

Unusual eye signs in Wegener's granulomatosis.

Wegener's granulomatosis is a rare necrotising vasculitis not easily diagnosed due to the obscurity of its diverse clinical features. Despite its comparatively low incidence, the unusual ophthalmic manifestations seen in this disease warrant extra caution from attending rheumatologists. In this case, bilateral peripheral ulcerative keratitis preceded any systemic symptoms. Timely recognition of the significance of this ophthalmic complaint and prompt ophthalmological consultation can help achieve early diagnosis and treatment of this potentially fatal rheumatological disease.

Prioritization of cataract surgery: visual analogue scale versus scoring system.

BACKGROUND: The purpose of the present paper was to evaluate the variability of using a visual analogue scale (VAS) and to assess the feasibility of a priority-setting scoring system for prioritizing elective cataract surgery. METHODS: Consecutive cases listed for cataract surgery were prospectively recruited. Ophthalmologists listed patients to undergo early or normal surgery and were asked to rate the urgency of surgery using a VAS. Patients were then reassessed and a cataract surgery prioritization (CSP) score was calculated based on the New Zealand priority criteria for cataract surgery. Correlation coefficients between VAS and CSP scores were calculated to determine the variability among ophthalmologists in using the VAS in prioritizing surgery. Further analyses were performed to assess the potential impact of implementing the CSP system. RESULTS: A total of 326 patients were recruited. There was a positive correlation between VAS and CSP scores (Spearman rho= 0.407, P < 0.001). A high degree of variation among ophthalmologists in the use of VAS was found. Patients with poor binocular vision were not listed as early, whereas patients with poor vision in the eye listed for cataract surgery but good vision in the fellow eye were more likely to be prioritized to have early operation. These findings suggest that patients with severe impairment in binocular visual function were not adequately accounted for during cataract surgery listing. CONCLUSIONS: The use of a VAS for prioritizing cataract surgery may be suboptimal due to high subjectivity. Adoption of an objective criteria-validated priority-setting scoring system may allow better stratification of patients to ensure better service provision.

Preoperative Antisepsis With Povidone-Iodine 5% in Cataract Surgery.

PURPOSE: This study aimed to evaluate the efficacy of povidone-iodine (PI) 5% as the only preoperative antiseptic in cataract surgery. DESIGN: Prospective interventional case series. METHODS: Fifty patients undergoing phacoemulsification under topical anesthesia in an outpatient surgery setting in a teaching hospital participated in the study. The preoperative antiseptic regimen consisted of instillation into the conjunctival sac and periorbital scrub with PI 5%. No topical antibiotic was given. Eyelid margin swabs were obtained for bacteriological culture before and after PI antisepsis and at the conclusion of surgery. The number of bacterial species isolated was compared with the Wilcoxon test. Anterior chamber aspirates were taken immediately before and after surgery to determine the rate of contamination. RESULTS: Bacteria were isolated from the eyelid margins of 48 patients (96%; 95% exact confidence interval, 86.3%-99.5%) before surgery, from the eyelid margins of 28 patients (56%) after antisepsis with PI 5%, and from the eyelid margins of 26 patients (56%; 95% exact confidence interval, 41.3%-70.0%) at the conclusion of surgery. The reduction of positive eyelid margin culture was statistically significant (P < 0.0001). Anterior chamber aspirates were positive in 3 patients. One patient with negative growth from anterior chamber aspirates developed culture-negative postoperative endophthalmitis. CONCLUSIONS: Because 56% of eyelids still have positive culture after PI 5% antisepsis, it might not be relied on as the sole preoperative antiseptic measure. Meticulous surgical technique, together with other modalities of preoperative and intraoperative antisepsis, should be used to prevent postoperative endophthalmitis.

Randomized double-masked controlled trial comparing pain scores with and without the use of supplementary 2% lidocaine gel in LASIK.

PURPOSE: To compare pain scores with and without supplementary topical 2% lidocaine gel in patients undergoing simultaneous bilateral laser-assisted in situ keratomileusis (LASIK) under topical anesthesia using 0.5% proparacaine eye drops. DESIGN: Randomized double-masked placebo-controlled trial. METHODS: Fifty-one Chinese subjects (102 eyes, with 51 eyes in each arm) were included. One eye was randomly allocated to have supplementary 2% lidocaine gel while the other eye received carbomer gel as control, in addition to topical 0.5% proparacaine. The pain scores for each eye during microkeratome flap creation, during laser ablation, and at 15, 30, and 45 minutes after LASIK were assessed. An overall pain score of the LASIK procedure was also obtained. Primary outcome measures were pain scores during and after LASIK. Secondary outcomes included need for additional topical anesthesia, patient cooperation score, and duration and complications of surgery. RESULTS: In the 2% lidocaine gel-treated group, the pain scores were significantly lower during microkeratome flap creation and laser ablation, and postoperatively at 30 and 45 minutes (P<.05 for all). Patients in the lidocaine gel group required less additional topical anesthesia (P=.0004) and were more cooperative (P=.019) as compared to the carbomer gel group. No surgical or postoperative complications were observed. CONCLUSIONS: The use of supplementary 2% lidocaine gel in LASIK is effective in lowering the pain experienced during and up to 45 minutes after LASIK.

Effectiveness of diode laser trans-scleral cyclophotocoagulation in patients following silicone oil-induced ocular hypertension in Chinese eyes.

We evaluated the effectiveness of diode laser trans-scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in nine patients having raised IOP following use of silicone oil (SO) for retinal detachment (RD) surgery in a retrospective observational case series. Diode laser TSCPC was applied at a power setting of 1.75 to 2.5 watts, for two sec with a maximum of 30 applications. The patients were followed up for 40 to 312 weeks. The mean pre-laser IOP was 32.06 mm Hg (SD 7.32). The mean post-laser IOP at one month, three months and six months was 17.89 mm Hg (SD 8.23), 21.89 mm Hg (SD 8.16) and 21.67 mm Hg (SD 7.55) respectively. The final IOP (at the last follow-up) was 19.56 mm Hg (SD 7.85) (P=0.021). Seven of them had undergone SO removal. In our observation, effectiveness of TSCPC in long-term control of SO-induced ocular hypertension was limited as compared to short-term control of IOP.

Tsukamurella: an unrecognized mimic of atypical mycobacterial keratitis? The first case report.

PURPOSE: The purpose of this study was to report on Tsukamurella as a mimic of atypical mycobacterial infection. METHODS: We report a patient who had received repeated corneal grafts with culture-proven Tsukamurella keratitis. RESULTS: A slow-progressing corneal abscess that initially developed adjacent to a corneal stitch responded poorly to empiric antibiotic treatment. A preliminary culture report revealed fast-growing mycobacterial species. Treatment adjustments successfully controlled the disease. A final diagnosis of Tsukamurella was subsequently made on the basis of cultures. CONCLUSIONS: Tsukamurella exhibits laboratory similarities to mycobacteria and should be considered in the differential of atypical infection of the ocular surface.